1. Field of the Invention
This invention relates to a method of automatically replicating data objects between a mobile device and a server; data replication is needed, for example, to back up data from the mobile device to the server and to ensure that the mobile device has the most up to date data held on the server. The mobile device and the server are connected over a wireless network, which may comprise a wide area network such as a cellular telephony network. The wireless network may also comprise a short range network, such as an 802.11 network, or a combination of short range, wide area and wire based connections.
2. Description of the Prior Art
Data replication between mobile devices (such as mobile telephones, smart phones, communicators and other kinds of wireless information device) and servers has attracted considerable attention. Reference may be made to PCT/GB2002/005308 and PCT/GB2002/005311 (to the present applicant), the contents of which are incorporated by reference.
One characteristic feature of wireless networks is the need to use bandwidth efficiently; this applies especially to wide area networks such as cellular networks, but also applies to other kinds of wireless networks, such as those based on 802.11 systems. The present invention is directed to increasing the efficiency of use of all such networks.
Cellular telephony network operators currently push data to mobile devices to update those devices with data, such as menus of the names of games that can be download to the mobile telephone. A simple example of efficient bandwidth useage is the practice of downloading these menus of games over night to make use of the available bandwidth.
To date, designers of data replication systems (as opposed to simple one-way push updating systems) have not been preoccupied with making efficient use of network bandwidth. This bias arises because the assumption behind most data replication systems is the need for immediate replication, irrespective of the impact on bandwidth.